The invention relates to a drive system having an electric motor. Depending on the type of electric motor used in the drive system, it can be necessary to couple an electronic assembly, for example in the form of an inverter, with the rotor of the electric motor in rotationally fixed manner.
The invention is based on the task of making available a drive system having an electric motor that has an electronic assembly mechanically coupled with the rotor, wherein the drive system demonstrates great thermal stability.
The invention accomplishes this task by means of a drive system having: an electric motor having a shaft, an electronic assembly, and a fan that is driven by the shaft, wherein the electronic assembly is coupled with the fan in rotationally fixed manner, and thermally coupled with it.
The drive system has an electric motor, for example in the form of a synchronous or asynchronous machine, having a driven shaft. The electric motor can be operated in motor mode and/or generator mode, for example.
The drive system furthermore has at least one electronic or electrical assembly, for example in the form of a circuit board and electrical components disposed on it, such as capacitors, resistors, microprocessors, etc. The electronic assembly can be configured, at least in parts, for functional control of the electric motor.
The drive system furthermore has at least one fan that is driven, indirectly or directly, by means of the shaft, which fan generates a cooling air stream.
The electronic assembly is mechanically coupled with the fan in rotationally fixed manner and rotates with it at the fan speed of rotation, on the basis of the rotationally fixed coupling, for example. The electronic assembly is additionally thermally coupled with the fan, so that heat flow from the electronic assembly in the direction of the fan can take place.
The fan can have a fan wheel or be a fan wheel, which is coupled with the shaft in rotationally fixed manner, wherein the electronic assembly is coupled with the fan wheel in rotationally fixed and thermal manner. For example, the electronic assembly can be screwed onto the fan wheel or onto a blade surface of the fan wheel, for example using a heat-conductive paste. The blade surface of the fan wheel can have a suitably shaped contact region, for example, which region has an essentially level surface having suitable dimensions.
The electronic assembly can be integrated into the fan wheel, for example in the form that the fan wheel or a corresponding part of the fan wheel forms a housing of the electronic assembly.
The electric motor can have a fixed housing and heat-generating electrical functional groups, particularly in the form of stator windings and/or rotor windings, wherein the functional groups are disposed within the housing, and the fan wheel and the electronic assembly are disposed outside of the housing.
A thermally insulating element can be disposed between the shaft and the fan wheel, which element minimizes a heat flow from the heat-generating electrical functional groups, by way of the shaft, in the direction of the fan wheel or of the electronic assembly.
The fan wheel can consist of a material having great thermal conductivity, for example aluminum alloys, other metal alloys and/or special ceramics.
The electric motor can have heat-generating electrical functional groups, particularly in the form of rotor windings, wherein the electronic assembly is electrically and/or mechanically contacted with the electrical functional groups by means of releasable electrical contacts.
The electrical contacts can comprise a number of contact segments, for example cylindrical segments, which are disposed over a circumference of the shaft, distributed uniformly or non-uniformly.
The electronic assembly can have at least one inverter or form one or more inverters, which is/are configured for the purpose of generating triggering signals for at least one rotor winding of the electric motor. The triggering signals can be triggering currents that are generated by means of the inverter, in such a manner that a magnetic rotary field having a predeterminable speed of rotation is brought about by means of the rotor winding.
Alternatively, the electronic assembly can have or form a rectifier circuit, as it is used in separately excited electric motors supplied with energy in contact-free manner, for example. There, electric energy is inductively transmitted in the direction of the rotor in the form of a magnetic alternating field, by way of auxiliary windings, and rectified there.
The electronic assembly can have means for wireless data transmission.